Reel driving device



F 1952 P. L. HOOVER ETAL 3 REEL DRIVING DEVICE Filed Oct. 18, 1947 2 SI'IEETFSHEET l .INVENTORS 0 ER DOIWLLL fl, 5/70/1727 BY I M 777 M 'rr auevs 1952 P. L. HOOVER ETAL REEL DRIVING DEVICE 2 SHEETSSHEET 2 Filed Oct. 18. 1947 S M m S R m fiw c. R V 0 WW m A HA, 9 0 L m M 0/ v. m OZ 6 7.

- come a tangled mass.

Patented Feb. 5, 1952 REEL DRIVING DEVICE Paul L. Hoover, Cleveland, Ohio, and Donald A. Brunton, Needham, Mass.

Application October 18, 1947, Serial No. 780,652

This invention relates to a driving mechanism which is particularly useful in the operation of magnetic recorders and other devices wherein a length of wire, yarn, cord or the like must be wound from one spool or reel to another and then rewound back to the first spool.

-As applied to magnetic recorders which utilize a strand of wire or tape for recording sound, wherein the wire is payed out from one reel and wound onto another, considerable difiiculty has been encountered in regulating the relative rotation of the reels because as the wire is building up on one reel, the speed of the other must gradually vary in proportion to the increase of wire on the first reel. Moreover, it is important that the supply reel must not run too fast with relation to the take-up reel or otherwise the wire will be fed faster than it is wound up, with the result that the excess will fall in a loose bundle and be- When the wire is being rewound, the functioning of the two reels is reversed, hence, the mechanism must then operate in the reverse direction with the same limitations and conditions as existed during the operation in a forward direction.

Efiorts have heretofore been made to overcome the foregoing difliculty, but all types of mechanism which have come to our attention have been relatively complex, bulky and expensive to manufacture. One type has used a single motor which rotates in one direction only. Consequently, to effect either a forward or reverse direction of wire movement a manually operable disengageable device between the motor and the respective reels has been used. The objection to this arrange- J ment is the fact that the device can be inadvertently operated while the motor is running, thus producing disastrous results in tangling or breakage of the wire. A further objection is the complexity of the mechanism required to accomplish the intended purpose, and the liability of overrunning of the wire.

Another effort for overcoming the aforesaid objection has included the use of two motors, one of which was geared or positively connected to one reel, the other of which was positively connected to the other reel. In the operation of such mechanism power was applied only to one motor at a time, the other being carried alon as dead weight, thereby furnishing a desirable drag or friction to retard the idling reel. The difficulty with this arrangement, however, was that when the systemwas stoppedtheinertia of the drag motor caused the supply reel to continue the unwinding operation afterthe winding motor had stopped,

2 Claims. (01. 242-55) with the result that the wire would unwind in a tangled mass. An attempt was made to correct that situation by using automatic brakes so as to stop both motors as soon as the power to either motor was turned off, but that, however, increased the bulk and complexity of the system and rendered it most objectionable.

A third plan for attempting to solve the aforesaid difliculty involved the use of a capstan drive wherein the wire, after passing from the supply reel through the level wind device and recording head, made a turn around a capstan which was directly connected to the driving motor. Thus the speed of the wire was determined by the rotation of the capstan, hence, the take-up reel had to be driven only sufficiently fast to keep slack out of the wire. That, however, required the take-up reel to be connected to the main drive in such manner as to tend to rotate it faster than was necessary, and 'to compensate for differences in rotative speed of the capstan and take-up reel, some form of slipping clutch had to be utilized. To rewind the wire, the direction of motor rotation was reversed, but a gear shift had to be provided so as to drive the new take-up reel through another slipping clutch. This arrangement was more complex than the preceding types.

An object of the present invention is to construct mechanism by means of which two reels can be operated from a single source of rotation and wherein the mechanism is greatly simplified over anything previously known for accomplishing the same purpose. The invention additionally provides a construction by means of which the mechanism may be made more compact and more economical than any existing devices of which we are aware. v

In all devices heretofore known to us, the reels have been mounted on spaced axes, thus necessitating the mounting of each reel individually. The present invention contemplates as an additional object the provision of a mechanism by means of which the reels may be applied or removed as a unit to provide a so-called magazine loading, thereby greatly facilitating the changing of reels for substitution of the sound to be reproduced or to be recorded.

Referringnow to the drawings, Fig. 1 is a front view of an embodiment of the present invention; Fig. 2 is a section taken on a plane indicated by the line 2 2 in Fig. 1; Fig. 3 is an exploded telescopic view of the driving mechanism which embodies the presentinvention; Fig. 4 is a section taken on a plane indicated by the line 5-4 in Fig. 2; Figs. 5 and 6 are sections taken on planes inaround a pulley 34- on a shaft 35.

dicated by the correspondingly numbered lines in Fig. 2, showing the position of the driving parts upon rotation of the driving shaft in one direction; Figs. 7 and 8 are sections corresponding to Figs. and 6 respectively, and illustrating the position of the parts when the driving shaft is rotating in an opposite direction from that shown in Figs. 5 and 6, and Fig. 9 is a side view of a portion of the mechanism adjacent the reels and showing the brakin device that is used with the present invention.

In Figs. 1 and 2, there is illustrated a magnetic recorder and reproducer constructed. in. accord.- ance with the teaching of the present invention.

The unit includes a base i G which carriesthe reel.

supporting and driving mechanism embodying the present invention positioned at the left in Fig. l, and a loud speaker l l positioned at the right of Fig. l. The recorder and reproducer mechanism is illustrated as being contained within a frame constituting plates 12 and it which are suitably positioned in parallel relationship by spacing bolts 14. The plates are fastened in any convenient manner to the base, as by a threaded fastening member i5 which extends upwardly into the plate and from the base at spaced intervals. A suitable housing 56 may extend around the frame and the mechanism.

Our invention is illustrated in connection with a magnetic recording and erasing head indicated in general at 20, a recording medium in the form of a wire 2! and a pair of reels 2.2 and 23 between which the wire is wound during the recording or reproducing operation.

The mechanism for operating the reels comprises an electric motor 30, the shaft of which is indicated at 31. The shaft may be operatively connected to the reel by a speed reduction unit such as a pulley 32 on the motor shaft, a belt 33 which extends around the pulley and also The lastnamed shaft is journalled in the plates [2 and I3 and is operatively connected to the reel. shaft 49 by belt 39, The shaft40 is also journalled in the plates and projects forwardly of the plate 12 Sufiiciently far to accommodate the reels as shown in Fig. 2;.

The connection between the shaft 49 and the reels is so constructed as to drive one of the reels whenever the motor rotates in one direction, at which time the other reel is automatically idled, and to drive the other reel, whenever the motor is rotated in the opposite direction, while at the same time the first reel is automatically idled. Such mechanism, in the preferred embodiment, is; shown in Fig. 3, wherein the. shaft; 49, has; re.- cesses 4| and 42 extending longitudinally thereof, the recess 4|; being right; hand and the; recess; 42 being left hand asis shown; Figs. 5 and. 6;; Each recess gradually increases in depth from one end; to the other, the bottom being: a, curved surface and extending for an angular distance of about 60. A sleeve 45- is mounted for rotation on the. shaft and. has a length. sufficientv to cover the grooves 41 and 42. Radial slots- 4t and 4-7!- are disposed in opposite, ends of. the sleeve and in registration with the. grooves 4t and 4-2:, while rollers 59 and. 5! are disposed. within, the respective slots. The reels may be slidably mounted directly upon the sleeve 45, but we prefer. to utilize; auxiliary sleeves 55 and 55. to which the respective: reels, are.v rigidly fastened. as by keys, which fit in keywaysil and 5&1851268? tively. Thus, whenthe. unit is-assembled and a collar 5 9 holds the various elements together,-

the reels can be detachably connected to the respective sleeves without the endangering of the position of the rollers in their respective slots. For all practical purposes, however, the sleeves 55 and 56 may be regarded as the hubs of the respective reels.

The diameter of each roller 50 and 5| is greater than the wall thickness of the sleeve 45, but less than the. distance between the inner wall of the auxiliary sleeve and the deepest portion of the associated groove in the shaft 40. Thus, whenever a roller such as 50 in Fig. 5 is in the deep part of the recess 4| which happens whenever the shaft 40 is turning clockwise, the auxiliary sleeve 45 and, therefore, the reel 23 carried thereby is in free wheeling or idling position with respect to the shaft 4t. At the same time, the roller 5! is wedged between the high point of the groove 42 and the wall of the auxiliary sleeve 58, thereby effecting a driving connection between the shaft 40- and the reel 22.

Whenever the direction of motor rotation is reversed, the roller 50 moves up on the recess 4| and effects a driving connection between the shaft 40 and the sleeve 55 and, therefore, between the shaft 40 and the reel 23. At the same time, the roller 51 moves into the deep part of the groove or recess 42, whereupon the reel 22 automatically has a free wheeling or idling movement with respect to the shaft 40.

To impart sumcient drag to the free wheeling or idling reel, we have shown a brake which operates constantly and yieldably against both reels. In the preferred form, the brake comprises a strip 60 of leather or other suitable material which is rigidly fastened at one end to a bar SI and which extends downwardly sumciently far to engagev the flanges 62 and 63 on the reels 22 and 23, respectively. A resilient leaf spring 65, also carried by the bar 6|, exerts constant tension uponthe strip E0 to force it against the. reel flanges. To remove the reels it is only necessary to hold thebrake strip out of contact therewith against the tension of the spring 65.

A level wind device suitable for use with the present invention embodies a carriage 10 which supports the head 20 and carries guide pulleys H and 12 around which the wire extends as it passes from. one reel through the head and onto the other reel. The carriage extends diagonally with. respect to the axis of the pulley, as viewed. in top plan, so as tov facilitate the guiding of the wire from one. reel. to the other, and may be supported upon. by a bearing I5 which is slidably mounted upon a bar '15 that projects outwardly from the. plate l2. and may be rigidly connected at the other end to a. bar 18 that is mounted for reciprocation. on the plates !2 and I3. Recipro cation. may be. effected by. a heart-shaped cam which rotates. within. a. slot 8!, at the rearward end of the bar 18, asris shown particularly in Figs. 2 and 4. The cam 80 is mounted ona shaft 82which in turn is: connected to the motor 3.0. by. av speed reduction unit, indicated in general. at. 84.. Thus, as the motor rotates, the level wind device moves backward and forward. to wind the-wire in a level manner upon the take up. reel.

The present invention is suitable asa driving connection between two driven members from a single. motor and. is. not limited in its application that wire recording device; However, to completathesillustration of. a wirerecording. deviceithereaisishown in Fig. 1,. in general, a loud speaker. withsuitable controls for operating;v the unit. Thus, a switch 85 may operate to control the actuation of the motor either in a forward or reverse direction, and a receptacle 86 may be adapted for receiving a, microphone plug. The control knob 81 may constitute a volume control, the control knob 88 may comprise an offand-on switch as well as a tone control, and the control knob 90 may be used for determining whether the electrical unit will operate as a recorder or reproducer. At the left of the control knob 90 is one colored light 9| which is lit when the control knob 90 is moved to a position for operating the apparatus as a recorder, while a differently colored light 92 located at the right of the control knob 90 is lit when the knob 90 is moved to a position for causing the apparatus to operate as a reproducing unit.

The present invention is advantageous in that whenever one reel is being driven by the motor, the other is free to rotate either in a forward or reverse direction with respect to the rotation of thejlsh aft, thus allowing the supply roll to move faster or slower automatically as may be necessaryto compensate for the amount of material jwhich has been unwound therefrom. Thus, at the start of the operation when'the supply roll is full and the take-up roll is empty, f

the supply roll will be turning at a slower rate than at thejend of the operation when the conditions' are reversed. The present invention accomplishes the automatic connection and disengagement of the reels merely by reversing the direction of motor rotation without the need for complex manually shiftable devices between the source of power and the reels. The invention additionally is well adapted for magazine load ing of the reels, thereby greatly fl'icilitatingthev on the first-mentioned sleeve and providing a clutch surface for the rollers and operating to retain the rollers in the respective slots, each of said reels having a driving connection with one of the auxiliary sleeves, the diameter of each of said rollers being greater than the wall thickness of the first-mentioned sleeve, but less than the distance between the inner wall of the auxiliary associated sleeve and the deepest portion of the associated groove in said shaft.

2. A unitary driving mechanism for a plurality of oppositely run reels comprising in combination, a reversible shaft having cam grooves spaced axially therein and disposed substantially apart, a sleeve covering said grooves and mounted for rotative movement upon the shaft, said sleeve having radially extending slots therein in registration with the respective grooves, a roller in each slot, said rollers acting to key the sleeve to the shaft, auxiliary sleeves axially spaced on the first sleeve andcovering the slots therein to provide clutch surfaces for the respective rollers, each of said reels being detachably mounted on the respective auxiliary sleeves and being adapted to have a driving connection therewith, the diameter of each roller being greater than the wall thickness of the first sleeve but less than the distance between the inner wall of the associated auxiliary sleeve and the deepest portion of the associated groove in the shaft.

PAUL L. HOOVER. DONALD A. BRUNTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,078,357 Woodmansee et a1. Apr. 27, 1937 2,248,790 Stapelfeldt July 8, 1941 2,275,961 Heller Mar. 10, 1942 2,349,018 Tasker May 16, 1944 FOREIGN PATENTS Number Country Date 4,933 Australia Nov. 26, 1926 

